Bacteria to power laptops - can synthetic biology solve energy crisis?

You can power laptops - and, potentially cars - using hydrogen extracted from water. The trouble is that it takes a lot of electricity. A simpler way would be to do it naturally, using enzymes - proteins which catalyse reactions - and bacteria. These do exist: certain green algae and "cyanobacteria" can split water using photosynthesis to produce molecular hydrogen.

But to create a generation of cars that would run on water with some sludge in the back, we need to learn how to design our own bacteria and enzymes that can co-opt natural processes for our ends.

Natural hydrogen-producing enzymes are complex, often using metal atoms to help them work. "For many of the enzymes related to energy production, people have no idea how they are actually organised," says Giovanna Ghirlanda, a protein-design researcher at the University of Arizona.